Erin is the fifth named storm to develop during the Atlantic hurricane season, which started just over two months ago. Last week, Tropical Storm Dexter formed in the western Atlantic but didn't pose a threat to land. In early July, Tropical Storm Chantal made landfall on the Carolina coast, bringing deadly flooding to the region.

A tropical storm warning has been issued for North Carolina as Hurricane Erin churns up the east coast of the U.S. as a Category 2 storm.

Tropical Storm Erin formed Monday in the eastern Atlantic near the Cabo Verde Islands and could become a major hurricane north of Puerto Rico by the weekend.